The B+W 49mm Light Red MRC 090M Filter can be used to increase image contrast when photographing using a film camera system with black-and-white film installed.
This filter's effect corresponds to that of a Wratten 25 filter. Wavelengths of visible light that are apparent as green and blue colors to the human eye are suppressed, while visible light associated with yellow, orange, and red colors are able to more easily pass though the B+W 49mm Light Red MRC 090M Filter and into the lens it is mounted in front of. When photographing with this filter along with black-and-white film, green to blue-colored subjects within a scene are reproduced in very dark shades of grey than if a filter was not used. Simultaneously, yellow to red subjects are rendered in very light shades of grey.
When applied to black-and-white photography, the increased contrast provided by the B+W 49mm Light Red MRC 090M Filter can result in very dark skies with extremely defined clouds. Shades of green among foliage can become strongly differentiated from neighboring shades of yellow, orange, or red, while light skin tones can be rendered as white or near-white. Additionally, this filter can also minimize the presence of haze caused by the bluish cast of daylight.
To prevent internal ghosting and reflections, each glass surface includes eight layers of anti-reflection coating. This Multi-Resistant Coating (MRC) also offers greater protection to the filter substrate and helps it to stay clean for longer than with uncoated filters. B+W filters are constructed from Schott glass for increased optical clarity. This filter features an F-Pro brass filter ring for durability as well as jamming prevention .